• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.3981-3986
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• 2014

Ganoderma lucidum polysaccharides (GLP) extracted from Ganoderma lucidum have been shown to induce cell death in some kinds of cancer cells. This study investigated the cytotoxic and apoptotic effect of GLP on HCT-116 human colon cancer cells and the molecular mechanisms involved. Cell proliferation, cell migration, lactate dehydrogenase (LDH) levels and intracellular free calcium levels ($[Ca^{2+}]i$) were determined by MTT, wound-healing, LDH release and fluorescence assays, respectively. Cell apoptosis was observed by scanning and transmission electron microscopy. For the mechanism studies, caspase-8 activation, and Fas and caspase-3 expression were evaluated. Treatment of HCT-116 cells with various concentrations of GLP (0.625-5 mg/mL) resulted in a significant decrease in cell viability (P< 0.01). This study showed that the antitumor activity of GLP was related to cell migration inhibition, cell morphology changes, intracellular $Ca^{2+}$ elevation and LDH release. Also, increase in the levels of caspase-8 activity was involved in GLP-induced apoptosis. Western blotting indicated that Fas and caspase-3 protein expression was up-regulated after exposure to GLP. This investigation demonstrated for the first time that GLP shows prominent anticancer activities against the HCT-116 human colon cancer cell line through triggering intracellular calcium release and the death receptor pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2569-2574
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• 2015

Necroptosis, also known as "programmed necrosis", has emerged as a critical factor in a variety of pathological and physiological processes and is considered a cell type-specific tightly regulated process with mechanisms that may vary rather greatly due to the change of cell line. Here we used HT-29, a human colon cancer cell line, to establish a necroptosis model and elucidate associated mechanisms. We discovered that cobalt chloride, a reagent that could induce hypoxia-inducible $factor-1{\alpha}(HIF1{\alpha})$ expression and therefore mimic the hypoxic microenvironment of tumor tissue in some aspects induces necroptosis in HT-29 cells when caspase activity is compromised. On the other hand, apoptosis appears to be the predominant death form when caspases are functioning normally. HT-29 cells demonstrated significantly increased RIPK1, RIPK3 and MLKL expression in response to cobalt chloride plus z-VAD treatment, which was accompanied by drastically increased $IL1{\alpha}$ and IL6 expression, substantiating the notion that necrosis can induce profound immune reactions. The RIPK1 kinase inhibitor necrostatin-1 and the ROS scavenger NAC each could prevent necrosis in HT-29 cells and the efficiency was enhanced by combined treatment. Thus by building up a necroptosis model in human colon cancer cells, we uncovered that mechanically RIP kinases collaborate with ROS during necrosis promoted by cobalt chloride plus z-VAD, which leads to inflammation. Necroptosis may present a new target for therapeutic intervention in cancer cells that are resistant to apoptotic cell death.

• Animal cells and systems
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• v.15 no.1
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• pp.9-17
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• 2011

Colorectal cancer is the third leading cause of cancer-related death in Western countries. Chemotherapeutic agents with different mechanisms of action have shown an increase in cure rates. In the present study, we investigated the effect of a combination of low concentration of paclitaxel (taxol, 5 nM) and topoisomerase 1 inhibitor camptothecin (CPT) on HCT116 colon cancer cells. Although the viability of cells treated with taxol alone was similar to that of control cells, sequential treatment with taxol and CPT exhibited high cytotoxicity. However, the opposite sequence of treatment did not exert cytotoxic effects on HCT116 cells. This enhanced cytotoxicity of the sequential combination therapy was the result of mitotic arrest, which increased the level of $p21^{Cip1/WAF1}$ through the p38 mitogen-activated protein kinase (MAPK) pathway. Knockdown by $p21^{Cip1/WAF1}$ siRNA or treatment with a p38 inhibitor reduced the viability of cells sequentially exposed to taxol and CPT. Taken together, a low taxol concentration in combination with CPT induced mitotic arrest in HCT116 cells, leading to synergistic cell death through enhanced expression of $p21^{Cip1/WAF1}$ and p38 MAPK pathway. Therefore, taxol could playa role as a sensitizer of CPT in colon cancer cells.

• BMB Reports
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• v.41 no.11
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• pp.803-807
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• 2008

We investigated the expression of muscarinic acetylcholine receptors (mAChRs) and their possible involvement in the regulation of cell proliferation in four colon cancer cell lines (SNU-61, SNU-81, SNU-407, and SNU-1033) derived from Korean colon carcinoma patients. A ligand binding assay showed that all four cell lines expressed mAChRs. Treatment of the four cell lines with the cholinergic agonist carbachol led to the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). In SNU-407 cells, carbachol significantly stimulated cell proliferation, which could be abolished by the muscarinic antagonist atropine and the ERK1/2 kinase inhibitor PD98059. These results indicate that mAChRs specifically mediate the proliferation of SNU-407 colon cancer cells via the ERK1/2 pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.338-346
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• 2015

This study was performed to elucidate the anti-proliferative and apoptotic mechanism of flavonoids in HT-29 human colon cancer cells. We investigated the anti-proliferative activity of flavonoids in HT-29 human colon cancer cells via cell viability assay (MTT assay), caspase-3 activity, RT-PCR, and western blotting. We cultured HT-29 cells in the presence of various flavonoids (apigenin, rutin, naringenin, and myricetin) at a concentration of $100{\mu}M$. In the MTT assay, naringenin showed the strongest effect on cell viability in HT-29 colon cancer cells. Caspase-3 activity, a marker of apoptosis, significantly increased upon naringenin treatment. For RT-PCR, myricetin significantly increased Bax protein levels, naringenin increased p53 protein levels, and rutin reduced expression of the anti-apoptotic protein Bcl-2. Western blotting of HT-29 colon cancer cells showed that myricetin increased cleaved caspase-3 protein levels, naringenin significantly increased poly (ADP-ribose) polymerase protein levels, and rutin increased E-cadherin protein levels. These results indicate that flavonoid exerts anticancer effects on human colon HT-29 cells through a caspase-dependent apoptotic pathway.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.93-101
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• 2022

Hizikia fusiforme, a type of brown algae, is widely used in Asian cuisine. It has been reported to have various pharmacological effects. In this study, the effects of the ethanol extract from H. fusiforme (EAHF) on the proliferation of human colon carcinoma cells were investigated. The effect on the survival of human hepatocarcinoma and colon carcinoma cells was examined, and results revealed that the anti-proliferative effects of EAHF were higher in colon carcinoma cells than in hepatocarcinoma cells. The inhibition of proliferation of HT29 colon carcinoma cells by EAHF treatment was closely related to the induction of apoptosis. EAHF treatment also increased caspase activity and poly(ADP-ribose) polymerase degradation, induced mitochondrial dysfunction, altered Bcl-2 family protein expression, and increased the rate of cytochrome c released from the mitochondria into the cytoplasm. Furthermore, the production of reactive oxygen species (ROS) was markedly stimulated by EAHF treatment, and when ROS production was blocked, EAHF-induced cytotoxicity was significantly attenuated. These results indicate that the anticancer activity of EAHF in HT29 colon carcinoma cells was induced by ROS-dependent mitochondrial impairment. While EAHF exhibited potent anticancer activity in colon carcinoma cells in this study, further studies on the active components of EAHF and their efficacy should be performed.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.280-286
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• 2003

Conjugated linoleic acid (CLA) consists of several geometric isomers of linoleic acid. CLA is found in foods derived from ruminants and exhibits strong anticarcinogenic effects in a variety of animal models. Matrix metalloproteinases (MMPs) play a key role in cancer progression. Specifically, MMP-2 and -9, which hydrolyze the basal membrane type IV collagen, are involved in the initial breakdown of collagen and basement membrane components during tumor growth and invasion. However, the effects of CLA on cancer cell motility and MMP expression and activity are not currently well known. Therefore, the present study examined whether CLA reduces the activity of MMP and cell motility in SW480 and SW620 cells, the human colon cancer cell lines. Gelatin zymography and Western blot analysis revealed that phorbol 12-myristate 13-acetate (PMA) induced the activity and protein expression of Mr 92,000 MMP-9 in both cell lines. To examine whether CLA inhibits the MMP activity, cells were incubated with 100 ngfmL PMA in the presence of various concentrations of CLA. PMA-induced MMP-9 activity was decreased by 20 $\mu$ M CLA in SW480 cells, and by 10 $\mu$ M and 20 $\mu$ M CLA in SW620 cells. Results from the Hoyden chamber assay showed that cell motility was increased by PMA and that PMA-induced cell motility was significantly decreased by 20 $\mu$ M CLA in SW480 cells. These results indicate that CLA may reduce the motility and MMP activity in human colon cancer cells.

• Molecules and Cells
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• v.37 no.7
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• pp.540-546
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• 2014

Several types of genetic and epigenetic regulation have been implicated in the development of drug resistance, one significant challenge for cancer therapy. Although changes in the expression of non-coding RNA are also responsible for drug resistance, the specific identities and roles of them remain to be elucidated. Long non-coding RNAs (lncRNAs) are a type of ncRNA (> 200 nt) that influence the regulation of gene expression in various ways. In this study, we aimed to identify differentially expressed lncRNAs in 5-fluorouracil-resistant colon cancer cells. Using two pairs of 5-FU-resistant cells derived from the human colon cancer cell lines SNU-C4 and SNU-C5, we analyzed the expression of 90 lncRNAs by qPCR-based profiling and found that 19 and 23 lncRNAs were differentially expressed in SNU-C4R and SNU-C5R cells, respectively. We confirmed that snaR and BACE1AS were down-regulated in resistant cells. To further investigate the effects of snaR on cell growth, cell viability and cell cycle were analyzed after transfection of siRNAs targeting snaR. Down-regulation of snaR decreased cell death after 5-FU treatment, which indicates that snaR loss decreases in vitro sensitivity to 5-FU. Our results provide an important insight into the involvement of lncRNAs in 5-FU resistance in colon cancer cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.633-640
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• 2004

This study was performed to investigate the cytotoxic effect of the water-extract from Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea in HCT-15 human colon carcinoma, AGS human gastric carcinoma and NIH3T3 mouse normal fibroblast cells using viable cell count and MTT assay. The water-extract from Chaga mushroom compositions induced inhibitory effects on proliferation of HCT-15 and AGS cells in the MTT assay and viable cell count. However, mouse normal NIH3T3 cells were exhibited 80% survival under the same condition. Chaga mushroom compositions showed highly antiproliferative effect in human cancer cell line HCT-15 and AGS, but not in mouse normal cell line NIH3T3. These results suggest that Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea are the candidate for chemoprevention in colon and gastric cancer.

• Korean Journal of Pharmacognosy
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• v.37 no.3
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• pp.130-135
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• 2006

The present study describes the preliminary evaluation of the cytotoxic activity of the extracts from Inula japonica. I. japonica was extracted with methanol, ethanol, acetone, and water, and then cytotoxic activity of these extracts were evaluated. The cytotoxic activity of each extract was assessed by the MTT-dye reduction assay. Both ethanol and acetone extracts from I. japonica showed the cytotoxic activity against the HT-29 human colon cancer cells. Furthermore, the ethanol extract was fractionated with n-hexane, diethyl ether, ethyl acetate, and water according to degree of Polarity, The diethyl ether fraction showed the highest cytotoxic activity against HT-29 cells, but the other fractions showed low cytotokic activity. In addition, diethyl ether layer also showed the cytotoxic activity against various tumor cells, such as human colon carcinoma SW620, human cervix adenocarcinoma HeLa, and human breast adenocarcinoma MCF-7 cells as well as HT-29 cells. These studies support that extracts of I. japonica may be a potential candidate as possible chemotherapeutic agent against human cancer.